petsc-master 2020-06-05
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SNESQNSetScaleType

Sets the scaling type for the inner inverse Jacobian in SNESQN.

Synopsis

#include "petscsnes.h" 
PetscErrorCode SNESQNSetScaleType(SNES snes, SNESQNScaleType stype)
Logically Collective on SNES

Input Parameters

snes - the iterative context
stype - scale type

Options Database

-snes_qn_scale_type <diagonal,none,scalar,jacobian> -

SNESQNScaleTypes

SNES_QN_SCALE_NONE - don't scale the problem
SNES_QN_SCALE_SCALAR - use shanno scaling
SNES_QN_SCALE_DIAGONAL - scale with a diagonalized BFGS formula (see Gilbert and Lemarechal 1989), available
SNES_QN_SCALE_JACOBIAN - scale by solving a linear system coming from the Jacobian you provided with SNESSetJacobian() computed at the first iteration of QN and at ever restart.

See Also

SNES, SNESQN, SNESLineSearch, SNESQNScaleType, SNESetJacobian()

Level

intermediate

Location

src/snes/impls/qn/qn.c

Implementations

SNESQNSetScaleType_QN in src/snes/impls/qn/qn.c

Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages